Siblings in Klipsch's Reference Premiere (RP) II series, so they share a family sound. It comes down to size, output and price.
| Area | Better | Why |
|---|
| Bass | A | Klipsch RP-504C II digs deeper - 50Hz against 58Hz. A subwoofer would even that out. |
| Amplifier needs | A | Klipsch RP-504C II is more sensitive (96dB vs 93dB), so it goes louder on the same amplifier. |
| Size | depends | Klipsch Reference Premiere RP 500SA II is easier to place; Klipsch RP-504C II is bigger, which usually goes with fuller bass. Your room decides. |
| Type | depends | A Passive Center Channel against a Passive Surround - a different job rather than a better one. |
| Price | B | Klipsch Reference Premiere RP 500SA II is cheaper - $450 against $799, about 44% less; arguably a different class. |
A Klipsch RP-504C II B Klipsch Reference Premiere RP 500SA II
depends neither is better in the abstract - it turns on your room, your system or how you will use them. Only specs published for both speakers are judged; anything missing on either side is left out rather than guessed.
Which should you choose?
The usual trade-off: Klipsch RP-504C II measures better, Klipsch Reference Premiere RP 500SA II costs about about 78% more% less. Whether that gap is worth the money is the call only you can make - and in a normal room it is often smaller than the numbers suggest. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 58Hz anyway, which makes the cheaper Klipsch Reference Premiere RP 500SA II much easier to justify. In a large or open-plan room, Klipsch RP-504C II has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, Klipsch Reference Premiere RP 500SA II is the easier speaker to get right.
And remember what a spec sheet cannot show: how each looks in your room and whether the finish suits it, what dealer support and warranty are like where you live, and how they actually sound to you. If you can hear them first - ideally with your own music - that will tell you more than any number above.